Air pilot valve



Nov. 13,1951 J. 1.. COONEY 2,575,209

, AIR PILOT VALVE Filed Jan. 28, 1 946 1 2 SHEETSSHEET l v r X9 70 53$ 1 .Z .CO0ney Patented Nov. 13, 1951 UNITED STATES PATENT OFFICE The present invention relates to pressure responsive valve apparatus and more particularly air pilot valves and the like regulatory fluidcontroll'ing devices.

One of the objects thereof is to provide a simple, efficient and inexpensive valve fitting equipped with fluid venting means therefor as well as controlling means therefor.

Another object of the invention is to provide, in a device of the kind described, means for regulating the fluid pressure in the valve casing or body whilst allowing venting of the air out of the casing.

Another object of the invention is to provide in a device of the character described an improved valve means for controlling the admissionof fluid into and out of the casing, which means also provides for venting the casing when necessary.

A still further object thereof is to provide, in

- a; device of the kind described, means for holding the valve to its fluid-controlling seat under spring pressure, with provision for freeing said valve from said spring pressure whenever this is desirable.

Another object of the invention is to provide, in a device of the character described, improved means controlling movements of the valve in its casing with a view to controiling simultaneously or separately its function of discharging fluid therefrom or air therefrom, as the case may be.

Another object thereof is to provide eflicient means for lubricating the frictional bearings of the fluid regulating means.

A final object of the invention is to provide reliable means for gaining access into any part of the valve structure for cleaning, replacement or repairing purposes.

With the above and other objects in view, my invention consists in the combination, arrangement and details of construction, disclosed in the drawings and specification, and then more particularly pointed out in the appended claims.

In the drawings:

Figure 1 is a side elevation of my invention.

Figure 2 is an end elevation thereof.

Figure 3 is a top plan view thereof.

Figure 4 is a sectional elevation thereof.

Figure 5 is a cross section taken on the line 5-5 of Figure 4.

Figure 6 is a side elevation of the valve proper.

I Figure 7 is a section detail of the upper part of my invention.

Figure 8 is a fragmental detail view showing a lever-engaging tappet.

Referring to the drawings, which are merely illustrative of my invention, I disclose the component details thereof. I A cylindrical valve casing I0 has a pair of diametrically opposite lugs II, Ila formed at its upper end, and has a fluid outlet nippe l2 internally threaded at I4 for the threaded reception of a pipe I3. At right angles relatively to outlet nipple I2, is an inlet fiuid' nipple I5, into whose internally threaded throat I6 is also threaded a pipe I1, the casing having a lateral outlet port forming a constricted orifice I8 which registers with outlet nipple I2.' Thecasing is formed with a coaxial chamber I 9. cylindrical in cross-section, and also with a valve inlet seat I9a extending at right angles to the outlet nipple I2, which seat has an inlet port 20 registering with inlet nipple I5.

The casing is formed, atits lower end, with an outwardly projecting arm 2| at right angles thereto, in which is" formed an elongated slot 22..

There is a valve bonnet or cap of cylindrical formation 23, which is formed at diametrically opposite points with lugs 24, 24a. The bonnet has a reduced boss 30 which seats Within cham'- ber I9 of the casing, and closes the chamber at this end. After lugs I I, I la are brought into registration coincidingly with lugs 24, 24a of the valve bonnet, cap screws 25 are threadedly tapped into. both sets of lugs, so that their screw heads 26.

abut the upper lugs 24, 24a as shown in Figure 2.

The surface 29, of the bonnet provides a valve seat at the end of the chamber I9 opposite to valve seat I9a, and the bonnet is formed with a cavity 28 which opens out of seat 29, and com-'- municates with chamber I9, as shown in Figure 4. A gasket 21 may be interposed between bonnet and easing, if desired. Communicating with cavity 28 is a lateral air vent orifice 3|, internally screw-threaded, which opens out to the atmosphere, and threaded into said orifice is a pin valve 32' upon whose outer end a clamping nut 34 is Opening out of the port 3|, at the top of-the bonnet, is an air' vent hole 33 that can be increased or decreased as desired by pin valve 82.

The bonnet is formed with a pair of oppositely arranged closely adjacent lugs or ears 35, 31' in a plane with the vent hole 33, and mounted between these ears on a pintle 32a is the inner rounded end 39 of a lever 40 having an oifset depressed portion M which terminates in a handle arm 42, making a fulcrum and lever upon whose upper edge is longitudinally formed a series of serrations or flutes 43. Lever 40 is fulcrumed on pintle' pin 3lawhich passes through one lug and is threaded into the other lug. One terminal 44 of an expansible coil spring 45, is hooked onto any of the flutes 43 of the handle 42 of lever 40, and its opposite terminal 46 is hooked onto a hook 41 formed upon one end of a screw bolt 49, entrance into the hook being had by inserting the spring hook into notch 48 ofthe hook 41. The screw bolt 49 projects through slot 22 of arm 2! and has an adjusting nut 50 also threadedthereon engaging above one face of the arm 2! and a nut which engages the other face of the arm, said latter nut having a circular knurled operating head or flange 52.

The lever 40 has an adjusting screw 53 tapped thereinto (Figure '7), held in set position therein by the lock nut 54 threaded onto its projecting end. Arranged to contact this screw 53 is the pusher rod 7| about to be described. The top 55a of the bonnet has a bore 55 formed therethrough which registers with its cavity 28.

I will now describe the special formation of valve employed in the valve casing. It is an allfiber piece, shaped to a cylindrical contour, as shown in Figure 6. Between its ends one or more flanges are formed .upon it, two being shown, designated 55 and 66. The lower valve seat engaging end of the valve is conically tapered, as at 51. This valve is mounted in chamber 19 being of lesser length with respect thereto, so that when its conical end 51 rests upon valve seat I 9a there will be clearance 62 between the opposite end of the valve and the valve seat surface 29 of the bonnet. As thus positioned in chamber l9, there is an annular channel 6! between the valve 55, and the adjacent wall of the chamber. The flanges 55, 55 of the valve make a snug engagement with the wall of the chamber. On them are formed, respectively, V-notches 68 and 69 which communicate with the annular channel 51.

A pusher pin '10 has a reduced forwardly pro- Y jecting terminal H which is slidably mounted in the bore 55a in the top of the bonnet 23 and its rounded extremity i2 is in contact with adjusting screw 53 on lever 48. The other end of the pusher pin is rounded, being centered into a correspondingly shaped conical cavity formed in a washer 64 made of metal, which is snugly fitted into the bottom of a chamber 63 formed in the valve 56 on one side of the cross partition 6| thereof. The pusher pin, in this way, is centered in both bonnet and valve for slidable movement in the bonnet. On the other side of partition 5! is formed a chamber 58 whose inner plane is pointed inwardly as at 59.

There is a small lever pivoted upon pin 14 mounted upon the lever 40 in eccentric relation to the hinge thereof, so that a minor portion of the length of this lever constitutes a cam 19 forming at 11 the widest part of the lever, the bottom-edge of the cam being straight, as at 18. The length of the minor portion of the lever 15 which is formed with the cam is greater than the distance between pivot pin 14, and the adjacent part of the top 55 of thebonnet, so when the lever 15 1S taken hold of and pulled upwardly to assum the perpendicular position shown in Figure 7, where the straight edge 18 of the cam 79 engages abuttingly this part of the bonnet, lever 40 upon which lever 15 is mounted will be elevated. The lever 15 is formed with a laterally offset shoulder 16 (Figures 1 and '7).

Lever 40 is formed with a lateral socket 86 (Figure 8) in the inner end of which is lodged a pressure spring 8!. One end of the spring is operatively fastened to a tiny ball 19a, which is pressed inwardly slightly by the lever cam 79 when said lever makes a side swipe against this ball in the course of its movement. The ball its will engage the edges of the cam 79 to hold the lever 15 against inadvertent rocking movement.

The operator turns the nuts 58, 5| for increasing or lessening the tension upon the spring 45, with regard to pulling down arm 42 of lever 40 a greater or lesser distance. The operator moves the spring away from or towards valve casing H], which lengthens or shortens the effective leverage on the arm 42 of lever 40 to vary the tension pull ing down arm 42 of lever 40, thus increasing or decreasing the air pressure required to raise valve 56 from its seat ISA. Since the screw 53 of lever 4lbears upon the rounded end 12 of the pusher pin 1 l, the exact amount of pressure upon this pin may be regulated by means of screw bolt 49, and in turn the pusher pin will press down upon valve 55, causing the outer conical'end 5'! thereof to contact firmly the valve inlet seat 19a. This closes the inlet port 20 of the casing,- if the spring. pressure imposed upon arm 42 of lever 40 is more; than sufiicient to balance the fluid pressure of the fluid seeking entrance into chamber 19 of the valve by way of inlet nipple 15. This pressure is, therefore, adjusted so that, if desired, fluid pres-' sure may lift valve and raise it from seatlQa, so as to uncover inlet port 20, the valve moving up wardly so as to contact seat 29 of the bonnet 23.

This position of the valve closes cavity 28 of the bonnet and as the valve moves upwardlyit carries pusher pin 1i along with it, the latter. pressing upwardly against lever 6t, and causing arm 42 of this lever to stretch the coils oi spring-v 49 yieldingly. As this takes place fluid is entering chamber [9 of the valve to raise it. Since there is now clearance between valve and seat [9a, some of the fluid enters the annular channel 61 between valve and chamber wall.

When valve closes cavity 28, at the end ofits upward stroke some of the fluid which got/into,

channel 61 by way of the V-notches 68, 59 in.

flanges B5, 55 of the valve is free to make exit out of orifice 18 into and out of outlet nipple 12 of the valve casing iii. For increased fluid pressures in chamber l9 of the valve or in the casing the spring-pressed lever 49 acts as a safety expedient, as it is raised accordingly under fiuid'pressurer against the valve. When a continuous flow of inclination illustrated in Figure 4. As long as lever 15 is in this vertical position, lever 40 is raised, valve 55 remains on seat 29 and acts as a stop to limit the upward movement of the pusher pin I I as shown in dotted lines in Figure :4.

The fluid, which is being discharged out of nip ple l2, no longer has to encounter spring opposi tion or pressure, but simply holds valve unseatecl from inlet port 20. The pusher pin maybe pressed downwardly by disengaging lever 15 fromthe valve bonnet, by turning it down into inclined position shown in Figure 1. As this takes place spring 45 contracts and pulls down upon arm 42 of lever 40, causing this lever to press valve 56 down upon seat l9a. This opens cavity 28, and when pin valve 32 is adjusted far enough, air vent 33 is uncovered so air may escape cut of chamber l9 to the atmosphere of cavity 28.

The pilot valve functions as follows: The compressor is started initially, it is assumed that there is no pressure on the receiver or lines connected thereto, the prime mover is energized through any medium, belt, steam or electricity, putting the compressor in motion, it being understood, that a compressor usually operates to supply a pre-determined pressure.

When this ore-determined pressure is reached, the pilot valve being set for it, then begins to function; the fluid air enters inlet port 29 moving piston valve 59 from its seat WA to the seat 29 on the bonnet 23. During this short interval of travel the fluid air is communicated to chamber 28 to air vent orifice 3i and to atmosphere through air vent hole 33 that intersects air vent orifice 3| in the bonnet. Piston valve 59 remains in this position in contact with seat 29 in the bonnet as long as the air of predetermined pressure remains constant allowing air to escape through the orifice l8 which registers with the outlet nipple l2. This is attached to a device known as an unloader; this device frees the compressor of its load.

When pressure on piston 56 drops a pre-determined amount, tension on spring 45 which is attached to lever 42 by its upper loop, exerts a downward pull on arm 42 of lever 49 depressing the push pin 10 which transfers this motion through its lower extremity to piston valve 56 thereby, returning valve 56 to its seat 19A over the chamer 29 causing the valve on the unloader to close, thereby, causing the compressor to begin to function and load up the receiver to the aforementioned pre-determined pressure for which the pilot is set. This cycle is repetitive as long as the prime mover continues to function or air is reduced below the predetermined pressure in the lines.

In the rounded end 39 of lever 40 is a hole 18 at right angles to lever 40 which opens out into the space 38 between lever 40 and the bonnet 23. It will be noted that during the cycle of the valve small quantities of air are discharged to the atmosphere, carrying along with same minute particles of oil which have access to the bell mouth orifice in rounded end 39 of lever 40, thereby lubricating pintle pin 31A when it passes through lever 40 at its rounded end 39 and since orifice 33 is larger than the bell mouth orifice the excess impinges on the adjacent walls of lever 40 and lugs 36 and 31, thoroughly lubricating them.

I claim:

1. An air pilot valve comprising a casing formed with a fluid inlet port at one end thereof, a vent port at the other end thereof, and a fluid outlet port disposed therebetween which is constantly in communication with whichever of said first two ports is open, a valve slidable in said casing closing said fluid inlet port at one end and closing said vent port at the other end of said casing, spring means including a lever on said casing biasing said valve to inlet port closing position, said casing formed with a vent orifice above said valve, and an aperture bearing boss for said lever in alignment with said vent orifice for lubricating said bearing.

2. An air pilot valve comprising a casing formed with a fluid inlet port at one end thereof. a vent port at the other end thereof, and a fluid outlet port disposed therebetween which is constantly in communication with whichever of said first two ports is open, a valve slidable in said casing closing said fluid inlet port at one end and closing said vent port at the other end of said casing, spring means including a lever on said casing biasing said valve to inlet port closing position, said casing formed with a vent orifice above said valve, an aperture bearing boss for said lever in alignment with said vent orifice for lubricating said bearing, and valve means regulating said vent orifice.

3. An air pilot valve comprising a casing having an upwardly opening cylindrical bore formed therein, a reduced diameter fluid inlet port formed in the lower end of said casing and communicating with said bore, a head member on said casing formed with a downwardly opening bore therein adapted to communicate with said casing bore, a lateral tapped passage formed in said head member and communicating at its inner end with said head bore, an upwardly opening vent port formed in said head member and communicating with said tapped passage, a threaded valve in said tapped passage adapted to regulate the flow through said vent port, a lateral fluid outlet port formed in said casing and communicating with said cylindrical bore intermediate the length of the latter, a valve member slidable within said cylindrical bore formed with circumferentially extending notched ridges and adapted to close said downwardly opening head member bore at the upper end of said casing, and said fluid inlet port at the lower end of said casing, said fluid outlet port being in constant communication with whichever is open, a pair of ears formed on said head and supporting a pivot pin in the plane of said vent port, a sprin pressed lever having a boss on one end pivotally carried by said pin, an aperture formed in said boss communicating with said pivot pin and adapted to confront said vent port, and a plunger extending through said head for engagement with said lever and said valve member.

JOHN L. COONEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 231,592 Leach Aug. 24, 1880 972,281 Stamets Oct. 11, 1910 1,523,716 Raymond Jan. 20, 1925 1,601,943 Conrader Oct. 5, 1926 2,049,211 Loweke July 28, 1936 2,272,926 Squiller Feb. 10, 1942 FOREIGN PATENTS Number Country Date 96,092 Sweden Apr. 27, 1939 

